Pesticide exposure in the womb linked to lower IQ in children

Risk: One study children who had the highest levels of an organophosphate in their umbilical cord as newborns had the lowest IQs by the age of seven

Mothers-to-be who eat foods tainted by pesticides could be
unwittingly stunting the intelligence of their unborn children, research
suggests.

The warning follows three separate studies part-funded by
the US government and linking exposure to insect ides in the womb to lower IQ
on starting school.

In the most striking of the studies, every ten-fold increase
in the chemicals detected during a woman’s pregnancy corresponded with a 5.5
point drop in her child’s IQ score at the age of seven.

University of California researcher Brenda Eskenazi said:
‘That difference could mean, on average, more kids being shifted into the lower
end of the spectrum of learning and more kids needing special services in
school.’

The professor started by testing samples of urine given by
pregnant women for evidence that common pesticides called organophosphates had
been in their systems.

She then keep track of the women and had their children sit
intelligence tests when they reached the age of seven.

This flagged up the drop in IQ, as well as lower scores in
tests of memory, reasoning and other skills.

The link held even when other factors such as socio-economic
class and education were taken into account.

The women studied lived in a farming community – but two
further studies of US city-dwellers backed up the finding.

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One measured levels of an organophosphate called
chlorpyrifos in the umbilical cords of babies born in New York.

By the age of seven, those with the highest levels had IQs
that were almost three points lower than those with the lowest levels.
Working memory was also poorer.

Lead author Virginia Rauh said: ‘Working memory
problems may interfere with reading comprehension, learning and academic
achievement, even if general intelligence remains in the normal range.’

The third study also linked the crop chemicals with stunted
intelligence – and showed that a gene carried by some mothers seemed to make
their children particularly vulnerable to the effect of pesticides in the womb.

A farmer uses a tractor to spray a barley crop: Campaigners say it is not surprising that powerful chemicals, designed to attack the brains and nerves of insects, could also harm man

Hugh Tilson, editor of the journal Environmental
Health Perspectives, which published the three studies, said: ‘As
a group, these papers add substantial weight to the evidence linking
organophosphate pesticides with adverse effects on cognitive development by
simultaneously reporting consistent findings for three different groups of
children.’

Some of the chemicals studied, such as chlorpyrifos, are no
longer used in homes in the UK, others have been withdrawn completely.
However, chlorpyrifos is still used on cereal crops such as malt and barley and
on apples.

Pesticide manufacturers say theirs is the most
tightly-regulated sector of the chemical industry.

But campaigners say it is not surprising that the powerful
chemicals, designed to attack the brains and nerves of insects, also harm man,
as the two share many of the same building blocks of life.

Elizabeth Salter Green, director of campaign group CHEM
Trust, said: ‘The foetus developing on the womb is particularly sensitive as
this is when much of the neurological wiring is going on. If that
neurological wiring is disrupted this can be seen in developmental affects
leading to lower IQs after birth.

Kids’ brains are not like plugs - they cannot be rewired -
so the sensible way forward is to replace such chemicals with safer
alternatives to avoid such exposures in the first place.’

The Crop Protection Association, which represents pesticide
manufacturers, said the chemicals are extensively tested before and after
reaching the market. New pesticides take an average of ten years to satisfy
more than 200 tests, at a cost to the manufacturer of £250million per product.

Dominic Dyer, the trade body’s chief executive, added that
pesticides play a vital role in the production of abundant and affordable
crops.